木质素-聚乳酸-聚己内酯嵌段共聚物对聚乳酸复合膜降解性能的影响  

Effect of Lignin-PLA-PCL Block Copolymer on the Degradation Properties of Polylactic Acid Composite Films

作　　者：郑倩男 王邓峰 刘琳[1] ZHENG Qiannan;WANG Dengfeng;LIU Lin(School of Materials Science&Engineering,Zhejiang Sci-Tech University,Hangzhou 310018,China)

机构地区：[1]浙江理工大学材料科学与工程学院,浙江杭州310018

出　　处：《生物质化学工程》2025年第2期23-29,共7页Biomass Chemical Engineering

基　　金：国家自然科学基金资助项目(22375181)。

摘　　要：以木质素(L)、L-丙交酯和ε-己内酯(ε-CL)为原料通过开环聚合制备了木质素-聚乳酸-聚己内酯嵌段共聚物(L-PLA-PCL),并与聚乳酸(PLA)共混制备了聚乳酸复合膜(L-PLA-PCL/PLA)。L-PLA-PCL作为生物质功能填料使得聚乳酸复合膜的拉伸强度由39.2 MPa(PLA)增加到41.8 MPa,断裂伸长率由2.5%(PLA)增加到27.4%;紫外光透过率由91%(PLA)降低到81.4%。考察了L-PLA-PCL在不同pH值磷酸盐缓冲液中对聚乳酸复合膜质量损失、熔融结晶性能和微观结构的影响,结果表明:L-PLA-PCL的添加改变了L-PLA-PCL/PLA的降解行为,PLA薄膜在pH值为6的磷酸盐缓冲液中降解速率最大,60 d后的质量损失率为48.13%,基体材料的降解主要发生在薄膜的非晶区。而L-PLA-PCL/PLA复合膜在pH值为8的磷酸盐缓冲液中降解最快,60 d后的质量损失率为39.23%,基体材料的降解主要发生在薄膜的表面。L-PLA-PCL在聚乳酸复合膜内先发生降解,在降解过程中造成L-PLA-PCL/PLA复合膜表面和内部的结构破坏。L-PLA-PCL/PLA复合膜具有优异力学性能和紫外光屏蔽性,并展现出与PLA薄膜相当的降解能力,是一种理想的可降解生物质复合材料。Lignin(L),L-propylcaprolactone andε-caprolactone(ε-CL)were used as raw materials to prepare lignin-poly(lactic acid)-poly(caprolactone)block copolymers(L-PLA-PCL)via ring-opening polymerization,and PLA composite films(L-PLA-PCL/PLA)were prepared by blending with PLA.As a biomass functional filler,L-PLA-PCL increased the tensile strength from 39.2 MPa(PLA)to 41.8 MPa,the elongation at break increased from 2.5%(PLA)to 27.4%,and UV transmittance decreased from 91%(PLA)to 81.4%.The effects of L-PLA-PCL on the mass loss,melting crystallization properties and microstructure of PLA composite films in phosphate buffers with different pH values were investigated.The results showed that the addition of L-PLA-PCL changed the degradation behavior of L-PLA-PCL/PLA,and the degradation rate of PLA films was the highest in phosphate buffer with pH value of 6,with a weight loss rate of 48.13%after 60 d.The degradation of the matrix material mainly occurred in the amorphous region of the films.The L-PLA-PCL/PLA composite film degraded fastest in phosphate buffer with pH value of 8,with a weight loss rate of 39.23%after 60 d.The degradation of the matrix material mainly occurred on the surface of the film.L-PLA-PCL degraded first within the PLA composite film.It causes structural damage to the surface and interior of the L-PLA-PCL/PLA composite film during the degradation process.The L-PLA-PCL/PLA composite film had excellent mechanical properties and UV-shielding properties,and showed a comparable degradation ability to PLA film,which was an ideal degradable biomass composite material.

关 键 词：木质素 聚乳酸 降解 结晶度 微结构 

分 类 号：TQ35[化学工程]